Palliative care is often the only option for people with CNS injuries - too little is known about the regeneration of adult axons to cure such damage. However, on ,Gabel and colleagues describe how C. elegans can provide insights into neural regeneration. Using femtosecond laser ablation to cut the axons of specific neurons in adult worms, the researchers show that, as in mammals,neurons in the head rarely regenerate after injury but those in the body reliably regrow. Next, they show that axonal regeneration in the worm's AVM mechanosensory neuron involves exploratory axonal outgrowth and pruning of unwanted axons. By contrast, the initial development of this neuron involves the stereotyped projection of a pioneer axon. Finally, by examining AVM regeneration in worms that lack various axonal guidance molecules, the researchers show that neural wiring during development and rewiring during regeneration have different molecular requirements. Thus, they suggest, C. elegans could be used in genetic screens for new molecules involved in the regeneration of adult neurons.
